There is a minor problem with the Conflagration Staff which causes it to be difficult to aim the charged attack at a distance. See this link for details and visual representation. I believe it is possible to have a mod solve this issue in a specific way. The Hide UI mod allows the user to hide the character's weapons and hands alongside the UI elements at the press of a button. The author of said mod has also stated that it's possible to hide only the weapons or only the arms. There is also the mod UI Tweaks that allows the player to hide player outlines while holding the Inspect Character keybind, which means it is possible for mod functions to be tied to specific pre-existing keybinds and actions. Combining this logic, here is how I think a mod can be used to allow better visibility with the Conflag Staff:

• First and foremost this mod should have no effect unless the Conflagration Staff is equipped and being wielded. I think this should be feasible considering we already have mods that only function when using specific things like the Bolt Staff or any melee weapon with the Parry trait.
  
• When charging the circular area attack (holding Right Mouse Button) the mod would simply hide Sienna's hand in first-person view. I'd prefer it to only hide Sienna's left hand if possible but if both hands are tied to the same function then obviously the only recourse is to make both hands invisible.
  
• Well, I guess that's it, really. Just hide Sienna's hand(s) while holding RMB with the Conflag Staff and revert visibility upon releasing the button. Then you should be able to fully see the flame circle while aiming afar.

Thank you for your consideration.